The overall goal of the project is to combine precise biophysical measurements of rheological properties during clot structure formation with biochemical measurements to examine various aspects of the kinetics of the human coagulation mechanism. The goals for the current year are to examine in detail the effects of platelet metabolic state on platelet-fibrin interaction and to study the effects of fibrinolytic drugs on structure formation and dissolution. We are interested in looking quantitatively at the relationship between the state of platelet membrane proteins and platelet-fibrin interaction during clot structure formation. This will involve altering the state in vitro (for instance the state of phosphorylation of certain membrane proteins) and then carrying out a dynamic mechanical testing during structure formation. Protein alterations will be quantitated using combinations of radio-labeling techniques and gelelectrophoresis (1- and 2-dimensional).